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[Calcium metabolism in arterial hypertension. II. Changes in thrombocyte sensitivity to verapamil]
Biulleten' Vsesoiuznogo Kardiologicheskogo Nauchnogo Tsentra AMN SSSR
|January 1, 1988
Insights
Verapamil effectively lowers calcium in hypertensive patients
Area of Science:
- Pharmacology
- Cardiovascular Medicine
- Cell Biology
Background:
- Hypertension is associated with altered calcium handling in platelets.
- Verapamil is a calcium channel blocker used in hypertension management.
Purpose of the Study:
- To investigate the effect of verapamil on platelet calcium concentration in hypertensive patients.
- To explore factors influencing verapamil sensitivity in these patients.
Main Methods:
- Dose-dependent inhibition of adenosine diphosphate (ADP)- and thrombin-activated fibrinopeptide (TAF)-induced calcium increase in platelets was measured.
- Half-maximal inhibitory concentration (EC50) was determined for verapamil.
- The influence of epinephrine and papaverine on verapamil sensitivity was assessed.
Main Results:
- Verapamil demonstrated dose-dependent inhibition of ADP- and TAF-induced platelet calcium increase.
- Epinephrine weakened verapamil's efficacy, while papaverine enhanced it.
- Individual sensitivity to a papaverine-verapamil combination was observed in hypertensive patients.
- Clonidine reduced verapamil sensitivity, which was restored by papaverine.
Conclusions:
- Verapamil modulates platelet calcium levels in hypertensive individuals.
- Platelet sensitivity to verapamil is influenced by other vasoactive substances like epinephrine, papaverine, and clonidine.
- These findings suggest potential for personalized therapy in hypertension management.
Abstract:
Verapamil produced dose-dependent inhibition of ADP- and TAF-induced increase in thrombocyte calcium concentration in hypertensive patients. Sensitivity to verapamil tested by EC50-half-maximal inhibition of responses to hormones can be weakened in vitro by adrenalin and strengthened by papaverin. Thrombocytes of hypertensive patients were individually sensitive to combination of papaverin and verapamil. The cellular sensitivity to verapamil disappeared when clonidine was substituted for verapamil and was restored when papaverin was added to verapamil.